Ptychodactis aleutiensis, a new species of ptychodactiarian sea anemone (Cnidaria: Anthozoa: Actiniaria) from the Aleutian Islands, Alaska

Abstract

We describe a new species of ptychodactiarian sea anemone, Ptychodactis aleutiensis, and redefine the family Ptychodactiidae and the previously monotypic genus Ptychodactis to accommodate P. aleutiensis sp. nov. Individuals of the new species were photographed and collected at depths of less than 20 m off the Aleutian Islands, Alaska. Many were found detached, adrift in the water. The species differs from the only other member in its genus, Ptychodactis patula, in having more tentacles, tentacles only at the margin, frilled structures associated with only two siphonoglyphs, infertile primary mesenteries, oral stomata, holotrichous nematocysts of two size classes in the tentacles, actinopharynx, and mesenterial filaments, and by the morphology of the holotrichs and spirocysts. It is the fourth species of ptychodactiarian described; Ptychodactis is the only genus of suborder Ptychodacteae with more than one species.

Keywords:

• Bering Sea
• Hexacorallia
• Ptychodacteae
• sub-Arctic
• taxonomy

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

Funding was provided through US Environmental Protection Agency Cooperative Office of Research and Development Agreement CR-83172801-1 to Alaska Department of Environmental Conservation Alaska Monitoring and Assessment Program (AKMAP) (Douglas Dasher) and University of Alaska Fairbanks (UAF) Institute of Marine Science (SCJ). DG Fautin acknowledges support from the US National Science Foundation (NSF) grant EF05- 31779 (on which she is co-investigator, in the program Assembling the Tree of Life). We thank SMNH and USNM for loaning us specimens of Ptychodactis patula. We thank Brenda Konar (UAF) for in situ photographs of Ptychodactis aleutiensis sp. nov. from the 1990s, and for providing the opportunity for HC to collect specimens on her 2008 NSF research cruise. We gratefully acknowledge Bodil Bluhm (UAF) for providing us with a Bering Strait specimen of P. patula, Seth Danielson (UAF) for providing the map of the Aleutian Islands, and Roger Clark (Santa Barbara Museum of Natural History) for photographs and information on the ecology of P. aleutiensis sp. nov.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark